code: def laf_to_three_points(laf: Tensor) -> Tensor:
      """Convert local affine frame(LAF) to alternative representation: coordinates of LAF center, LAF-x unit vector,
      LAF-y unit vector.
  
      Args:
          laf:  :math:`(B, N, 2, 3)`.
  
      Returns:
          threepts :math:`(B, N, 2, 3)`.
      """
      KORNIA_CHECK_LAF(laf)
      three_pts = stack(
          [
              laf[..., 2] + laf[..., 0],
              laf[..., 2] + laf[..., 1],
              laf[..., 2],
          ],
          dim=-1,
      )
      return three_pts
  
imports: import math
  from typing import List, Optional, Tuple, Union
  import torch
  import torch.nn.functional
  from kornia.core import Tensor, concatenate, cos, sin, stack, tensor, zeros
  from kornia.core.check import KORNIA_CHECK_LAF, KORNIA_CHECK_SHAPE
  from kornia.geometry.conversions import angle_to_rotation_matrix, convert_points_from_homogeneous, rad2deg
  from kornia.geometry.linalg import transform_points
  from kornia.geometry.transform import pyrdown
label_desc: Use image node_id 18 for calling a global function with example usage: laf_to_three_points(laf) and returns: three_pts